Internal combustion engines are well known and widely used for vehicle propulsion, production of rotational power in virtually innumerable machines, and electrical power generation. Burning of a combustible fuel and air within one or more cylinders in an internal combustion engine produces a rapid pressure rise to drive a piston that rotates a crankshaft according to well-known principles. Burning of the fuel and air produces heat and increases temperatures of engine components such that some form of active cooling is required in virtually all applications.
Most modern internal combustion engines include a cylinder block having the cylinders formed therein, and a cylinder head that includes intake and exhaust conduits, valves, and often fuel delivery devices. Depending upon the engine type, an igniter such as a sparkplug or a prechamber ignition device is also supported in the cylinder head. The internal geometry of the cylinder head can be relatively complex to accommodate multiple coolant passages for conveying a cooling fluid through the cylinder head to dissipate heat from combustion.
Cylinder head geometry, materials, component positioning, component type, and other properties have been varied in many different ways over the years in attempts to optimize cooling efficacy. Where internal combustion engines or components are not sufficiently cooled, various problems in the nature of cracking, thermal fatigue, seizure of moving parts, or even melting of materials can occur. Insufficient cooling efficacy can also limit the manner in which an engine can be operated. Since the capacity for heat rejection in an engine can relate to a quantity of fuel that can be burned in each combustion cycle, overall engine power output can be limited at least in a general sense by the engine's capacity to dissipate heat. The precision and control of ignition timing can also be impacted by cooling efficacy. Hot spots in engine components exposed to the heat of combustion can cause ignition to occur at a timing or in a manner that is different than what is intended. U.S. Pat. No. 2,716,970 to Earl et al. is directed to a Means for Directing Water in the Cylinder Head of an Internal Combustion Engine. Earl et al. proposed a design that provided a water distributor containing a specially-shaped orifice to direct coolant toward the deck surface of the cylinder sealing wall, apparently to increase turbulence in the flow of coolant over critical areas of the deck and ultimately limit lime deposits.